The invention relates to a transmission and reception device having a reception device and a transmission device disposed next to each other and to a two-way optical transmission configuration.
For the two-way transmission of data via glass fibers, it is necessary to have transmission and reception components respectively at both ends of a glass fiber section, which may be reciprocally assigned to one another. In data transmission, it is necessary to ensure that the transmitter on one side of the transmission section and the receiver on the other side have good optical coupling to the glass fiber. In the prior art, for example, transmission/reception devices are known in which, using controllable branching elements such as optical splitters or the like, the transmitter or the receiver can respectively be coupled optically to the-glass fiber. Besides such devices, which have a relatively complicated structure, there are however also simple structures in which the transmitter and the receiver remain optically coupled to the glass fiber. It is devices of this type that the present application addresses.
In a generic transmission/reception device of this type, a transmission diode is placed close beside a reception diode (photodiode) on a support material. Coupling curves respectively show a degree of coupling or a coupling efficiency with respect to a lateral displacement between an input/output end of a glass fiber and the transmission diode or the reception diode, respectively. The glass fiber is adjusted centrally between the transmission and reception diodes. Optimum data transmission is achieved when the fiber axis runs through a point of intersection of the coupling curves. The disadvantage with this configuration is, however, that the fiber axis in each case intersects with the steep sides of the coupling curves, and a lateral fiber offset therefore leads to a relatively strong loss on transmission or on reception.
It is accordingly an object of the invention to provide a two-way optical transmission and reception device which overcomes the above-mentioned disadvantages of the prior art devices of this general type, which has improved coupling in that a lateral fiber offset leads to a smaller coupling loss.
With the foregoing and other objects in view there is provided, in accordance with the invention, in a bi-directional optical transmission configuration having a glass fiber with an input/output end, a transmission/reception device, containing:
a reception device; and
a transmission device, the reception device, the transmission device, and the input/output end of the glass fiber disposed optically in series with respect to one another.
The invention proposes that the transmission device, the reception device and the input/output end of the glass fiber are disposed optically in series with respect to one another. This provides the possibility of aligning the components optically with one another, that is to say placing the maxima of the coupling curves of the transmission device and of the reception device at one position in the lateral direction, and adjusting the input/output end of the glass fiber in such a way that the fiber axis runs through these maxima.
The advantage of the invention is, on the one hand, that the fiber axis runs through the maxima of both coupling curves and therefore permits more efficient input and output coupling of the optical radiation. On the other hand, in the event of a fiber offset, the fiber axis does not move along the steep sides of the coupling curves, but in the region of the maximum here the coupling does not change very strongly. A fiber offset therefore leads only to a moderate change in the transmission properties.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a two-way optical transmission and reception device, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.